title: The effects of aging on postural control and selective attention when stepping down while performing a concurrent auditory response task.
abstract: OBJECTIVE
  To investigate the effects of aging on postural control and cognitive performance in single- and dual-tasking.
  
  
  METHODS
  A cross-sectional comparative design was conducted in a university motion analysis laboratory. Young adults (n = 30; age 21.9 ± 2.4 years) and older adults (n = 30; age 71.9 ± 6.4 years) were recruited. Postural control after stepping down was measured with and without performing a concurrent auditory response task. Measurement included: (1) reaction time and (2) error rate in performing the cognitive task; (3) total sway path and (4) total sway area after stepping down.
  
  
  RESULTS
  Our findings showed that the older adults had significantly longer reaction times and higher error rates than the younger subjects in both the single-tasking and dual-tasking conditions. The older adults had significantly longer reaction times and higher error rates when dual-tasking compared with single-tasking, but the younger adults did not. The older adults demonstrated significantly less total sway path, but larger total sway area in single-leg stance after stepping down than the young adults. The older adults showed no significant change in total sway path and area between the dual-tasking and when compared with single-tasking conditions, while the younger adults showed significant decreases in sway.
  
  
  CONCLUSIONS
  Older adults prioritize postural control by sacrificing cognitive performance when faced with dual-tasking.
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China, william.tsang@polyu.edu.hk.
authors.forename: William W N
authors.initials: WW
authors.lastname: Tsang
authors.forename: Nazca K Y
authors.initials: NK
authors.lastname: Lam
authors.forename: Kit N L
authors.initials: KN
authors.lastname: Lau
authors.forename: Harry C H
authors.initials: HC
authors.lastname: Leung
authors.forename: Crystal M S
authors.initials: CM
authors.lastname: Tsang
authors.forename: Xi
authors.initials: X
authors.lastname: Lu
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001288:Attention; D016022:Case-Control Studies; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D004856:Postural Balance; D011597:Psychomotor Performance; D011930:Reaction Time; D057190:Stroop Test; D016138:Walking